In the last few decades, 3-D printing has become a reality--no longer the stuff of science fiction. It's mostly known for its capability to create prototypes, spare parts and other objects cheaply, quickly and accurately, but the technology is starting to find its place in biotech and medicine.

Now, a few biotech companies are exploring this new frontier in science with hopes of creating tissues and organs for medical research and therapeutic applications. One of those, San Diego-based Organovo, has developed a bioprinting method to create strips of liver tissue, about 20 cells thick, to use for experimental drug testing. The company is focusing on liver cells because of their wide use in the laboratory to evaluate the potential toxicity or efficacy of drugs.

Organovo listed on the NYSE MKT, a trading venue with the NYSE Euronext market, on July 11. Also last month, it forged an important partnership with Springfield, VA-based Methuselah Foundation, in which the regenerative medicine-focused public charity said it would commit to funding research at major academic institutions that use Organovo's proprietary NovoGen bioprinting technology.

Organovo presented its first fully cellular 3-D bioprinted liver tissue data in April at the 2013 Experimental Biology conference in Boston. According to the company, this was the first time truly 3-D human liver tissues were generated from bioprinting. The tissue produced is made up of multiple cell types arranged in distinct spatial patterns that replicate features of natural tissue architecture. The company reported that the tissue "demonstrated excellent functional characteristics that replicates human biology better than what has come before."

Then there's Austin, TX, biotech startup TeVido BioDevices, which is developing a 3-D printing process that could fabricate breast tissue for use building custom implants and grafts for breast cancer patients.

Academic researchers are also experimenting with bioprinting. The Scripps Clinic in San Diego has figured out how to engineer bioartificial cartilage in cow tissue and printed cartilage in tissue taken from patients who had knee replacement surgery. And Hannover Medical School in Germany is among several institutions experimenting with bioprinting skin cells.

As for Organovo, it's not churning out any meaningful profit yet--it reported revenues of only $0.2 million in the first three months of 2013--but as bioprinting catches on, time will tell whether the company's business model is viable in the long-term.